I have a B&O Beocenter 3500 in for repair. The lift/start/stop mech just doesn’t work, it has a thin metal lever arm which has many bends and twists in it, which engages the cam which in turn moves the tone arm. None of this is happening. I have a service manual that doesn’t help, I can’t find any photos on the internet showing the mechanism. Don’t know If anyone has any experience with this unit.
A difficulty with this mecanism is that you can’t normallly watch it operate, as it’s on the underside of the deck. You say nothing happens. Have you tried pressing the button gently and keeping it depressed for a second or so? Does the platter start spinning when you press the button?
I have seen cases, where too much friction between the metal arm on the microswitch and the actuator arm that rubs against it inside the contact housing kept it from activating. Clean the parts and add a little teflon oil to lower the friction.
And, as mentioned above, the deck will not work correctly upside down, which makes it a little tricky to diagnose and test.
The unit does nothing is to press the button, whether it’s a short or long press.
The unit will work if move the lever to engage the motor switch, so the turntable rotates fine and the tone arm will drop. But when it returns to it’s rest position, you can’t restart it.
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